This section of the FEDERAL REGISTER

contains notices to the public of the proposed

issuance of rules and regulations. The

purpose of these notices is to give interested

persons an opportunity to participate in the

rule making prior to the adoption of the final

rules.

Proposed Rules Federal Register

105483 

Vol. 89, No. 248 

Friday, December 27, 2024 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2024–2712; Project 

Identifier AD–2024–00145–E] 

RIN 2120–AA64 

Airworthiness Directives; General 

Electric Company Engines 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The FAA proposes to adopt a 

new airworthiness directive (AD) for 

certain General Electric Company (GE) 

Model CF34–8C1, CF34–8C5, CF34– 

8C5A1, CF34–8C5A2, CF34–8C5A3, 

CF34–8C5B1, CF34–8E2, CF34–8E2A1, 

CF34–8E5, CF34–8E5A1, CF34–8E5A2, 

CF34–8E6, and CF34–8E6A1 engines. 

This proposed AD was prompted by a 

predicted reduction in the cyclic life of 

the combustion chamber assembly 

(CCA) forward flange. This proposed AD 

would require fluorescent penetrant 

inspections (FPIs) of the CCA for any 

indications and replacement if 

necessary. The FAA is proposing this 

AD to address the unsafe condition on 

these products. 

DATES: The FAA must receive comments 

on this proposed AD by February 10, 

2025. 

ADDRESSES: You may send comments, 

using the procedures found in 14 CFR 

11.43 and 11.45, by any of the following 

methods: 

• Federal eRulemaking Portal: Go to 

regulations.gov. Follow the instructions 

for submitting comments. 

• Fax: (202) 493–2251. 

• Mail: U.S. Department of 

Transportation, Docket Operations, M– 

30, West Building Ground Floor, Room 

W12–140, 1200 New Jersey Avenue SE, 

Washington, DC 20590. 

• Hand Delivery: Deliver to Mail 

address above between 9 a.m. and 5 

p.m., Monday through Friday, except 

Federal holidays. 

AD Docket: You may examine the AD 

docket at regulations.gov under Docket 

No. FAA–2024–2712; or in person at 

Docket Operations between 9 a.m. and 

5 p.m., Monday through Friday, except 

Federal holidays. The AD docket 

contains this NPRM, any comments 

received, and other information. The 

street address for Docket Operations is 

listed above. 

FOR FURTHER INFORMATION CONTACT: 

Alexei Marqueen, Aviation Safety 

Engineer, FAA, 2200 South 216th Street, 

Des Moines, WA 98198; phone: (781) 

238–7178; email: alexei.t.marqueen@

faa.gov. 

SUPPLEMENTARY INFORMATION: 

Comments Invited 

The FAA invites you to send any 

written relevant data, views, or 

arguments about this proposal. Send 

your comments to an address listed 

under the ADDRESSES section. Include 

‘‘Docket No. FAA–2024–2712; Project 

Identifier AD–2024–00145–E’’ at the 

beginning of your comments. The most 

helpful comments reference a specific 

portion of the proposal, explain the 

reason for any recommended change, 

and include supporting data. The FAA 

will consider all comments received by 

the closing date and may revise this 

proposal because of those comments. 

Except for Confidential Business 

Information (CBI) as described in the 

following paragraph, and other 

information as described in 14 CFR 

11.35, the FAA will post all comments 

received, without change, to 

regulations.gov, including any personal 

information you provide. The agency 

will also post a report summarizing each 

substantive verbal contact received 

about this NPRM. 

Confidential Business Information 

CBI is commercial or financial 

information that is both customarily and 

actually treated as private by its owner. 

Under the Freedom of Information Act 

(FOIA) (5 U.S.C. 552), CBI is exempt 

from public disclosure. If your 

comments responsive to this NPRM 

contain commercial or financial 

information that is customarily treated 

as private, that you actually treat as 

private, and that is relevant or 

responsive to this NPRM, it is important 

that you clearly designate the submitted 

comments as CBI. Please mark each 

page of your submission containing CBI 

as ‘‘PROPIN.’’ The FAA will treat such 

marked submissions as confidential 

under the FOIA, and they will not be 

placed in the public docket of this 

NPRM. Submissions containing CBI 

should be sent to Alexei Marqueen, 

Aviation Safety Engineer, FAA, 2200 

South 216th Street, Des Moines, WA 

98198. Any commentary that the FAA 

receives which is not specifically 

designated as CBI will be placed in the 

public docket for this rulemaking. 

Background 

The FAA received a report from the 

manufacturer that an analysis was 

conducted during a ream repair of the 

aft flange bolt hole of the high-pressure 

compressor. The analysis determined 

that the cyclic life of the CCA forward 

flange bolt holes adjacent to the 

compressor case horizontal split line is 

lower than the current certified limit. 

This condition, if not addressed, could 

result in failure of the CCA before 

reaching the published life limit, 

uncontained release of the CCA, damage 

to the engine, and damage to the 

airplane. 

FAA’s Determination 

The FAA is issuing this NPRM after 

determining that the unsafe condition 

described previously is likely to exist or 

develop on other products of the same 

type design. 

Proposed AD Requirements in This 

NPRM 

This proposed AD would require FPIs 

of the CCA forward flange for any 

indications and replacement as 

applicable. 

Costs of Compliance 

The FAA estimates that this AD, if 

adopted as proposed, would affect 2,988 

engines installed on airplanes of U.S. 

registry. 

The FAA estimates the following 

costs to comply with this proposed AD: 


khammond on DSK9W7S144PROD with PROPOSALS
105484 Federal Register / Vol. 89, No. 248 / Friday, December 27, 2024 / Proposed Rules 

ESTIMATED COSTS

Action Labor cost Parts cost Cost per 

product 

Cost on U.S. 

operators 

FPI the CCA forward flange ........................... 8 work-hours × $85 per hour = $680 ............. $0 $680 $2,031,840 

The FAA estimates an average CCA 

utilization of 2,143 part cycles per year. 

Based on this life estimate, the FAA is 

providing an estimated annual cost to 

replace these parts. The FAA estimates 

that 369 affected engines will require 

CCA replacement at 28,500 part cycles 

since new (PCSN), 855 affected engines 

will require CCA replacement at 25,500 

PCSN, and 1,764 affected engines will 

require CCA replacement at 40,000 

PCSN. The following summarizes the 

costs of the proposed AD over the 

analysis timeframe, for the 12 years 

spanning 2024–2036. The cost of early 

CCA removals, required by this 

proposed AD, analyzed over 2024 

through 2036, are $265 million at a 2% 

financial discount rate. 

Action Labor cost Parts cost Cost per 

product 

Cost on U.S. 

operators 

annualized 

(2% discount 

rate) 

Replace the CCA (prorated part cost) ............ 8 work-hours × $85 per hour = $680 ............. $646,900 $647,580 $24,544,532 

Authority for This Rulemaking 

Title 49 of the United States Code 

specifies the FAA’s authority to issue 

rules on aviation safety. Subtitle I, 

section 106, describes the authority of 

the FAA Administrator. Subtitle VII: 

Aviation Programs, describes in more 

detail the scope of the Agency’s 

authority. 

The FAA is issuing this rulemaking 

under the authority described in 

Subtitle VII, Part A, Subpart III, Section 

44701: General requirements. Under 

that section, Congress charges the FAA 

with promoting safe flight of civil 

aircraft in air commerce by prescribing 

regulations for practices, methods, and 

procedures the Administrator finds 

necessary for safety in air commerce. 

This regulation is within the scope of 

that authority because it addresses an 

unsafe condition that is likely to exist or 

develop on products identified in this 

rulemaking action. 

Regulatory Findings 

The FAA determined that this 

proposed AD would not have federalism 

implications under Executive Order 

13132. This proposed AD would not 

have a substantial direct effect on the 

States, on the relationship between the 

national government and the States, or 

on the distribution of power and 

responsibilities among the various 

levels of government. 

For the reasons discussed above, I 

certify this proposed regulation: 

(1) Is not a ‘‘significant regulatory 

action’’ under Executive Order 12866, 

(2) Would not affect intrastate 

aviation in Alaska, and 

(3) Would not have a significant 

economic impact, positive or negative, 

on a substantial number of small entities 

under the criteria of the Regulatory 

Flexibility Act. 

List of Subjects in 14 CFR Part 39 

Air transportation, Aircraft, Aviation 

safety, Incorporation by reference, 

Safety 

The Proposed Amendment 

Accordingly, under the authority 

delegated to me by the Administrator, 

the FAA proposes to amend 14 CFR part 

39 as follows: 

PART 39—AIRWORTHINESS 

DIRECTIVES 

■ 1. The authority citation for part 39 

continues to read as follows: 

Authority: 49 U.S.C. 106(g), 40113, 44701. 

§ 39.13 [Amended] 

■ 2. The FAA amends § 39.13 by adding 

the following new airworthiness 

directive: 

General Electric Company: Docket No. FAA– 

2024–2712; Project Identifier AD–2024– 

00145–E. 

(a) Comments Due Date 

The FAA must receive comments on this 

airworthiness directive (AD) by February 10, 

2025. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to the following General 

Electric Company (GE) Model engines: 

(1) CF34–8C1, CF34–8C5, CF34–8C5A1, 

CF34–8C5A2, CF34–8C5A3, and CF34– 

8C5B1 engines with an installed combustion 

chamber assembly (CCA) having part number 

(P/N) 4145T11G08, 4145T11G10, 

4180T27G02, 4180T27G04, or 4923T82G02; 

and 

(2) CF34–8E2, CF34–8E2A1, CF34–8E5, 

CF34–8E5A1, CF34–8E5A2, CF34–8E6, and 

CF34–8E6A1 engines with an installed CCA 

having P/N 4145T11G08, 4145T11G09, 

4180T27G01, or 4180T27G03. 

(d) Subject 

Joint Aircraft System Component (JASC) 

Code 7240, Turbine Engine Combustion 

Section. 

(e) Unsafe Condition 

This AD was prompted by a predicted 

reduction in the cyclic life of the CCA 

forward flange. The FAA is issuing this AD 

to prevent failure of the CCA. The unsafe 

condition, if not addressed, could result in 

failure of the CCA before reaching the 

published life limit, uncontained release of 

the CCA, damage to the engine, and damage 

to the airplane. 

(f) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(g) Required Actions 

(1) For affected Group 1 engines with an 

installed CCA having less than 15,000 part 

cycles since new (PCSN) as of the effective 

date of this AD, before the accumulation of 

28,500 PCSN, remove the CCA from service 

and replace with P/N 4180T27G08 or a later 

approved P/N. 

(2) For affected Group 2 engines with an 

installed CCA having less than 15,000 PCSN 

as of the effective date of this AD, before the 

accumulation of 25,500 PCSN, remove the 

CCA from service and replace with P/N 

4180T27G07 or a later approved P/N. 

(3) For affected Group 1 and 2 engines with 

an installed CCA having between 15,000 

PCSN and 24,999 PCSN as of the effective 

date of this AD, before the accumulation of 

25,000 PCSN, perform a fluorescent 

penetrant inspection (FPI) on the forward 

flange of the CCA for any indications. 


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Federal Register / Vol. 89, No. 248 / Friday, December 27, 2024 / Proposed Rules 105485 

(4) If no indications are found during the 

FPI required by paragraph (g)(3) of this AD, 

within 15,000 part cycles from the date of the 

FPI, remove the CCA from service and 

replace with P/N 4180T27G07, 4180T27G08, 

or a later approved P/N, as applicable. 

(5) For affected Group 1 and 2 engines with 

an installed CCA having more than 25,000 

PCSN as of the effective date of this AD, at 

the next engine shop visit after the effective 

date of this AD, perform an FPI on the 

forward flange of the CCA for any 

indications. 

(6) If no indications are found during the 

FPI required by paragraph (g)(5) of this AD, 

within 15,000 part cycles from the date of the 

FPI and not to exceed 41,100 PCSN, remove 

the CCA from service and replace with P/N 

4180T27G07, 4180T27G08, or a later 

approved P/N, as applicable. 

(7) If an indication is found during any FPI 

required by paragraph (g)(3) or (5) of this AD, 

before further flight, remove the CCA from 

service and replace with P/N 4180T27G07, P/ 

N 4180T27G08, or a later approved P/N, as 

applicable. 

(h) Definitions 

For the purpose of this AD: 

(1) ‘‘Group 1 engines’’ are GE Model CF34– 

8C1, CF34–8C5, CF34–8C5A1, CF34–8C5A2, 

CF34–8C5A3, and CF34–8C5B1 engines. 

(2) ‘‘Group 2 engines’’ are GE Model CF34– 

8E2, CF34–8E2A1, CF34–8E5, CF34–8E5A1, 

CF34–8E5A2, CF34–8E6, and CF34–8E6A1 

engines. 

(3) An ‘‘engine shop visit’’ is the induction 

of an engine into the shop for maintenance 

involving the separation of major mating 

engine case flanges, except for the following 

situations, which do not constitute an engine 

shop visit: 

(i) Separation of engine flanges solely for 

the purposes of transportation of the engine 

without subsequent maintenance. 

(ii) Separation of engine flanges solely for 

the purposes of replacing the fan or 

propulsor without subsequent maintenance. 

(i) Installation Prohibition 

After the effective date of this AD, do not 

reinstall any CCAs that were removed as a 

result of paragraphs (g)(1), (2), (4), (6), and (7) 

of this AD in any engine. 

(j) Alternative Methods of Compliance 

(AMOCs) 

(1) The Manager, AIR–520 Continued 

Operational Safety Branch, FAA, has the 

authority to approve AMOCs for this AD, if 

requested using the procedures found in 14 

CFR 39.19. In accordance with 14 CFR 39.19, 

send your request to your principal inspector 

or local Flight Standards District Office, as 

appropriate. If sending information directly 

to the manager of the AIR–520 Continued 

Operational Safety Branch, send it to the 

attention of the person identified in 

paragraph (k) of this AD and email to: 

AMOC@faa.gov. 

(2) Before using any approved AMOC, 

notify your appropriate principal inspector, 

or lacking a principal inspector, the manager 

of the local flight standards district office/ 

certificate holding district office. 

(k) Additional Information 

For more information about this AD, 

contact Alexei Marqueen, Aviation Safety 

Engineer, FAA, 2200 South 216th Street, Des 

Moines, WA 98198; phone: (781) 238–7178; 

email: alexei.t.marqueen@faa.gov. 

(l) Material Incorporated by Reference 

None. 

Issued on December 19, 2024. 

Suzanne Masterson, 

Deputy Director, Integrated Certificate 

Management Division, Aircraft Certification 

ervice. 

[FR Doc. 2024–30785 Filed 12–26–24; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2024–2713; Project 

Identifier AD–2024–00328–T] 

RIN 2120–AA64 

Airworthiness Directives; The Boeing 

Company Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The FAA proposes to adopt a 

new airworthiness directive (AD) for 

certain The Boeing Company Model 

777–200, –200LR, –300, –300ER, and 

777F series airplanes. This proposed AD 

was prompted by a report indicating 

that an airplane experienced a 

glideslope (G/S) beam anomaly during 

an instrument landing system (ILS) 

approach, which resulted in a higherthan-expected descent rate during the 

final segment of an ILS approach. The 

flightcrew might follow misleading 

flight director (F/D) guidance after 

disconnecting the autopilot, without 

reference to the other available 

information and flight deck indications. 

This proposed AD would require 

installing new autopilot flight director 

computer (AFDC) operational program 

software (OPS) and doing a software 

configuration check. The FAA is 

proposing this AD to address the unsafe 

condition on these products. 

DATES: The FAA must receive comments 

on this proposed AD by February 25, 

2025. 

ADDRESSES: You may send comments, 

using the procedures found in 14 CFR 

11.43 and 11.45, by any of the following 

methods: 

• Federal eRulemaking Portal: Go to 

regulations.gov. Follow the instructions 

for submitting comments. 

• Fax: 202–493–2251. 

• Mail: U.S. Department of 

Transportation, Docket Operations, M– 

30, West Building Ground Floor, Room 

W12–140, 1200 New Jersey Avenue SE, 

Washington, DC 20590. 

• Hand Delivery: Deliver to Mail 

address above between 9 a.m. and 5 

p.m., Monday through Friday, except 

Federal holidays. 

AD Docket: You may examine the AD 

docket at regulations.gov under Docket 

No. FAA–2024–2713; or in person at 

Docket Operations between 9 a.m. and 

5 p.m., Monday through Friday, except 

Federal holidays. The AD docket 

contains this NPRM, any comments 

received, and other information. The 

street address for Docket Operations is 

listed above. 

Material Incorporated by Reference: 

• For Boeing material identified in 

this proposed AD, contact Boeing 

Commercial Airplanes, Attention: 

Contractual & Data Services (C&DS), 

2600 Westminster Blvd., MC 110–SK57, 

Seal Beach, CA 90740–5600; telephone 

562–797–1717; website 

myboeingfleet.com. 

• You may view this material at the 

FAA, Airworthiness Products Section, 

Operational Safety Branch, 2200 South 

216th St., Des Moines, WA. For 

information on the availability of this 

material at the FAA, call 206–231–3195. 

It is also available at regulations.gov 

under Docket No. FAA–2024–2713. 

FOR FURTHER INFORMATION CONTACT: 

Michael Closson, Aviation Safety 

Engineer, FAA, 2200 South 216th St., 

Des Moines, WA 98198; phone: 206– 

231–3973; email: Michael.P.Closson@

faa.gov. 

SUPPLEMENTARY INFORMATION: 

Comments Invited 

The FAA invites you to send any 

written relevant data, views, or 

arguments about this proposal. Send 

your comments to an address listed 

under the ADDRESSES section. Include 

‘‘Docket No. FAA–2024–2713; Project 

Identifier AD–2024–00328–T’’ at the 

beginning of your comments. The most 

helpful comments reference a specific 

portion of the proposal, explain the 

reason for any recommended change, 

and include supporting data. The FAA 

will consider all comments received by 

the closing date and may amend this 

proposal because of those comments. 

Except for Confidential Business 

Information (CBI) as described in the 

following paragraph, and other 

information as described in 14 CFR 

11.35, the FAA will post all comments 

received, without change, to 

regulations.gov, including any personal 


khammond on DSK9W7S144PROD with PROPOSALS